Common aerosol spray cans have a cylindrical body and a domed top surface with a depressible, finger actuated nozzle located at the top of the dome. The design of the common spray can causes finger pain and hand fatigue. To address this problem, the prior art includes many spray can adapters having trigger arrangements intended to alleviate finger pain and hand fatigue. One of the problems with these types of trigger arrangements is that the user tends to lose their intuitive sense of touch or feel for the spray because the index finger is located remote from the push-button nozzle via some type of mechanical mechanism. It may take the user several minutes or more to obtain a comfortable sense of touch, if at all.
Most spray can users employ improper spraying techniques, which leads to overspray, excessive waste, paint runs and generally poor quality. The primary issue in this regard is failure to maintain the spray can at the appropriate standoff distance from the surface being painted. Horan et al. U.S. Pat. No. 6,896,192 describes a spray can targeting and positioning system which uses a light beam or a pair of light beams to help the user maintain the spray can at an appropriate standoff distance. Horan et al. U.S. Pat. No. 6,896,192 issued on May 24, 2005, is entitled “Spray Can Targeting and Positioning System”, assigned to the assignee of the present invention and is incorporated herein by reference. The Horan et al. '192 patent discloses several embodiments. In one embodiment, a light beam targeting and positioning system is mounted to the body of a handle triggering mechanism that attaches to the dome of a spray can. The triggering mechanism depresses the push-button nozzle on the spray can when the user pulls the trigger. The light beam targeting and positioning system in this embodiment is a dual beam type as disclosed in Klein et al. U.S. Pat. No. 5,598,972 issuing on Feb. 4, 1997 and entitled “Optical Spray Paint Optimization System And Method”, which is also assigned to the assignee of the present application, and is also incorporated herein by reference. This light beam targeting and positioning system uses a laser light source and a beam splitter to generate a pair of non-parallel light beams that propagate towards the surface being painted. The first light beam is fixed in its orientation and is often called the reference beam. Typically, the light beam targeting and position system should be mounted to the spray can so that a spot illuminated by the reference beam resides in the center of the spray pattern on the surface being painted. The angular orientation of the other beam, often called the gauge beam, can be adjustable, although this is not always desirable. The angular orientation of the gauge beam is selected so that it converges towards the reference beam. When the spray can is positioned at the proper standoff distance from the surface being painted, the spot illuminated on the surface by the gauge beam converges with the spot illuminated by the reference beam either to form a single point on the surface, or to become aligned either horizontally or vertically on the surface being painted. In this way, the user is provided constant feedback as to whether the spray can is properly positioned with respect to the surface being painted.
In another embodiment shown in the Horan et al. '192 patent, the light beam targeting and positioning system is not associated with a triggered handle assembly. Rather, it is attached to a spray can using a strap-like attachment device. In this embodiment, the user grips the spray can as normal and depresses the push-button nozzle with their index finger to spray paint onto the surface, but with the aid of the light beam targeting and positioning system mounted to the spray can, thereby providing feedback to the user as to the proper targeting and positioning of the spray can with respect to the surface being painted.
Another embodiment disclosed in the Horan et al. '192 patent application uses a single light beam spray gun positioning system as disclosed in U.S. Pat. No. 7,040,546, issuing on May 9, 2006 entitled “A Single Beam Spray Gun Positioning System”, which again is assigned to the assignee of the present application and is incorporated herein by reference. In the single beam system, the orientation of the single light beam is adjusted so that the light beam will illuminate at the center of the spray pattern on the surface when the spray gun is located at the appropriate standoff distance from the surface. The single beam system is a simpler mechanism than the dual beam mechanism, although it is not designed to provide accurate targeting feedback when the spray gun is not positioned at the appropriate standoff distance from the surface, as is provided by the reference beam in the dual beam system discussed above.
While these prior art patents certainly disclose the use of a light beam targeting and positioning system in connection with an aerosol spray can, they do not suitably address the issue of finger pain and hand fatigue in a practical fashion. As mentioned above, it is believed that users shy away from handle trigger arrangements because they loose their intuitive feel for the push-button nozzle. For example, when a user presses a push-button nozzle directly with their index finger, the user can immediately feel subtle rocking and/or pressure changes. Trigger mechanisms, in large part, eliminate this type of tactile feedback. On the other hand, the acute pressure exerted by the push-button nozzle on the index finger as well as the difficulty that some people have in grasping the body of the can for long periods of time can be quite annoying and tends to limit the amount of time that users are willing to paint with aerosol spray paint cans.
Another problem frequently facing spray can users is the lack of sufficient lighting for the surface being painted. This has been addressed in the prior art, for example, by placing a light on the front end of a trigger handle mechanism that is attached to a spray can. This feature can be particularly helpful in circumstances where lighting is poor and it is inconvenient or impractical to set up ancillary lighting.